Vito Corleone will loan you money on a "five$-$for$-$six" arrangement; i$.$e$.,$ for every $$5$ he gives you today, you give him $$6$ one week from now. What is the APR of this loan?

a$.$

$410\%$

b$.$

$1,040\%$

c$.$

$540\%$

d$.$

$860\%$

e$.$

$1,310\%$